Importance of Water in Maintaining Horses Health

EQUIMED STAFF - 05/03/2017

lean, fresh, palatable water - Necessity #1

The body of every living thing whether animal or plant is made up largely of water. Water is an extremely versatile molecule. It is the perfect liquid medium in which to dissolve nutrients for ingestion or wastes for excretion. With a large body, the horse needs clean, fresh, palatable water at least several times a day, if not free choice all the time.

Dehydration is often not recognized until 5 percent or more body weight is lost.

A horse's body contains 65 to 76 percent water with the 10 percent variation being accounted for by differences in age, amount of body fat and muscle mass, and the amount of exercise during any given period.

Water is essential for all metabolic activities and for a number of vital physiological processes including utilization and digestion of nutrients, regulation of body temperature, muscle contraction strength, joint lubrication, and waste elimination.

The typical horse weighing 1,000 to 1,200 pounds needs 8 to 10 gallons of water each day just for maintenance, and during strenuous exercise in hot, humid weather when the horse is sweating a great deal, it will need 2 to 3 times more. 

A lactating mare producing 3 gallons of milk a day needs at least 75 percent more water per day and during hot weather that need can increase significantly.

Many horses are given access to water only a couple of times a day.  Although horses can adapt to this practice, it is not always best for their health and well-being.  A horse going without water for a number of hours will begin to become dehydrated and the functioning of its body will begin to decline.

Caution - cold can cause colic

When temperatures are cold and drinking water temperatures approach freezing, a horse's water intake will usually decrease drastically.  This is not good, and, in fact can lead to problems such as impaction colic. 

According to research, horses prefer water that ranges between 45 and 65 degrees Fahrenheit, and will drink more water if it is in the proper temperature range.  Ask yourself, "Do you like to drink hot water on a hot day, or icy water when the temperature is around freezing?"  Neither does your horse!

During cold weather, care should be taken to make sure that water is warmed to a drinkable temperature.  This is extremely important for older horses or horses that have chronic illnesses.  An automatic heating element can be used in many cases to keep water at a drinkable temperature 

Water availability should never be left to chance.  Frozen water troughs, fouled water buckets, broken automatic systems, natural rivers or streams that are polluted or contaminated, wrong-size water buckets, water troughs filled with algae all lead to horses not getting enough fresh, clean, palatable water, and in the worst case scenario becoming dehydrated and ill because of lack of water.

Standing, stagnant water is a breeding ground for mosquitos and may become contaminated by rats and other rodents.  Algae which grows rapidly in stagnant water is often toxic and your horse can become ill or be poisoned if the algae is ingested. 

Fortunately, there are several effective ways for providing water for your horse and thereby making sure it maintains the proper fluid balance in its body for maximum health and efficiency.  Please see the following articles for more information about selecting a waterer for your horse: Selecting a Horse Waterer.

If you change your water system, be sure to work with your horse so that it adapts to the new system.  Some horses readily take to new ways of doing things including getting the necessary amount of water each day, but others need some training and time to adapt to a new system.

Buckets that are automatically filled several times a day, other automatic waterers, water troughs that are systematically cleaned and refilled regularly, heated water buckets or troughs used during cold weather, and many other options are available for the horse owner who wants to ensure the health of the horse by always having an accessible water supply available.

Maintaining your horse's fluid balance

In addition to making sure your horse always access to plenty of fresh, clean, palatable water, you should recognize when your horse is becoming dehydrated and its fluid balances need attention.

Dehydration is often not recognized until 5 percent or more body weight is lost.  Signs of dehydration are weakness, depression, sunken eyeballs, dry mucous membranes, slowed capillary refill time, and increased heart rate.

Quite often dehydration is caused by prolonged strenuous exercise in hot, humid weather.  An overworked horse that has lost too many fluids through sweat can become a victim of heat exertion which can be fatal if not addressed quickly.

In worst case scenarios where both temperature and humidity are high, the horse's systems can shut down quickly when the horse sweats, losing precious water and upsetting the electrolyte balance.

Being proactive by providing water frequently and supplementing electrolytes before, during, and after strenuous exercise or endurance riding is the best way to prevent serious dehydration.  Providing water and making sure the horse has sufficient salt just before performance has also been shown to be effective.

A quick way to check your horse's hydration level is to pinch the skin near the base of the horse's neck for 2 seconds.  If the skin returns to normal almost immediately, the horse is not seriously dehydrated. However, if the skin stays in the pinched position, the horse needs water and most likely electrolytes.

Also check your horse's capillary and jugular refill times and observe the mucous membranes, as well as listening for gut sounds that indicate your horse is becoming or is dehydrated.

According to research, a horse loses 75 mg of sodium chloride and 30 mg of potassium chloride in 25 pounds of sweat (Schott, 2002). Providing commercial electrolytes may be rather costly depending on how much you are using.  Research and information from veterinarians is available regarding making your own electrolyte solution.

If you choose to make your own electrolyte mix, you will need Sodium Chloride, Potassium Chloride, Calcium (carbonate/acetate) and Magnesium (oxide) in proportions of 60:30:5:5 which are the same ingredients in most commercial electrolytes. Commercial electrolytes also usually contain glucose, preservatives and sometimes anti-caking mixtures.

Once you have made your own mix, give your horse enough so that sodium levels are being replenished. The optimal replacement is 1 to 3 grams of sodium for every liter of water the horse drinks. If the horse is sweating profusely, it could be losing 6 or more grams of sodium each hour.

Do not give your horse too much electrolyte solution. Doing so can actually worsen dehydration according to research. Giving your horse plenty of free-choice water and measuring how much your horse is drinking, then adapting electrolyte supplementation to the horse's consumption of water is important.

In addition to strenuous exercise, certain diseases and conditions can affect your horse's fluid maintenance. Cases of diarrhea, fever, acute gastric dilation, intestinal obstruction and peritonitis can lead to dehydration and electrolyte imbalance. In some cases, intravenous solutions may be necessary if the horse's systems are near shut-down because of dehydration.

When your are shipping or transporting your horse, care must be taken to make sure your horse remains hydrated. Research shows that trips over 12 hours duration create great stress on a horse.

Water during horse transport

Making sure that your horse has water at least every four hours and some wet hay available during transport helps keep your horse properly hydrated and helps ensure the health and well-being of the horse.